title: Cytotoxicity, sister-chromatid exchanges and DNA single-strand breaks induced by 4-oxo-4-(3-pyridyl)butanal, a metabolite of a tobacco-specific N-nitrosamine.
abstract: The tobacco-specific N-nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), is metabolized by alpha-carbon hydroxylation to reactive diazohydroxides and aldehydes. The aim of this study was to determine the relative ability of one NNK-derived aldehyde, 4-oxo-4-(3-pyridyl)butanal, to induce cytotoxicity, sister-chromatid exchanges (SCEs) and DNA single-strand breaks (SSBs) in V79 cells. Our data demonstrate that this aldehyde is cytotoxic for V79 cells (IC50 = 0.4 mM) and induces SCEs at concentrations ranging from 0.01 to 0.5 mM. DNA SSBs were observed at concentrations ranging from 0.05 to 1 mM and were repaired within 8 h. When V79 cells were cultured with primary hepatocytes, there was a reduction in the frequency of SCEs induced by the aldehyde. This suggests that hepatocytes can partially deactivate the aldehyde. Our results suggest that this aldehyde is one of the reactive intermediates generated during NNK metabolism.
authors.affiliation: Laboratory of Cancer Etiology and Chemoprevention, School of Pharmacy, Laval University, Quebec City, Canada.
authors.forename: M A
authors.initials: MA
authors.lastname: Alaoui-Jamali
authors.forename: R
authors.initials: R
authors.lastname: Gagnon
authors.forename: N
authors.initials: N
authors.lastname: el Alami
authors.forename: A
authors.initials: A
authors.lastname: Castonguay
mesh_terms: D000818:Animals; D002460:Cell Line; D004277:DNA, Single-Stranded / Q000187:drug effects; D009153:Mutagens; D009602:Nitrosamines / Q000378:metabolism* / Q000633:toxicity; D010947:Plants, Toxic; D011725:Pyridines / Q000378:metabolism / Q000633:toxicity*; D012044:Regression Analysis; D012854:Sister Chromatid Exchange / Q000187:drug effects; D014026:Nicotiana / Q000032:analysis
chemical_list: D004277:DNA, Single-Stranded; D009153:Mutagens; D009602:Nitrosamines; D011725:Pyridines; C062145:4-oxo-4-(3-pyridinebutanal)